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From: bill@fedeva.UUCP (Bill Daniels)
Newsgroups: comp.protocols.tcp-ip,comp.dcom.lans
Subject: Query - Ethernet collisions
Keywords: LANalyzer, collisions, preamble
Message-ID: <98@fedeva.UUCP>
Date: 29 May 90 15:01:47 GMT
Organization: Federal Express Corp., Memphis, TN
Lines: 19

We recently acquired an Exelan LANalyzer.  During our first uses of it,
we noticed that about 40% of the packets on one ethernet segment (which
is remotely bridged to another) show up as "Collision detected in preamble".
This segment is not busy necessarily when this happens.  The actual number of
collisions reported seems fairly constant even as traffic picks up.  On
a very quiet net (~ 2 packets / sec.) I see about 20 errors over ~ 30 secs.
When the segment is a little more active (~ 1000 packets / sec.) the error
rate is just about the same.  

I have tried disconnecting the devices that the errors are associated with
but the collisions just move to the packets associated with other devices.

Any clues?

bd
-- 
bill daniels
federal express, memphis, tn
{hplabs!csun,mit-eddie!premise}!fedeva!bill